Archive for the ‘privacy’ Category

CACM Cover Story: Privacy Enhanced Personalization

August 15, 2007

The cover story of this month’s CACM is on privacy-enhanced personalization. Alfred Kobsa (UC Irvine professor and father of the field of privacy-enhanced personalization) devotes most of the piece to surveying privacy-related usability research. Most of the findings seem like common-sense:

  • Users tend to overvalue small, immediate benefits to disclosing personal information and undervalue potential future negative consequences.
  • Users fall into one of three camps: privacy fundamentalists (disclose nothing), the unconcerned (disclose everything), and privacy pragmatists (make sensible trade-offs)–with the two former classes on the decline and pragmatists on the rise.
  • Users value transparency (knowing how personal data will be used) and control.
  • Users will disclose more to established web sites and sites that have a professional appearance and a privacy policy.

No surprises there.

The tail end of the piece–where Kobsa surveys privacy-enhancing technology–is less fluff. The notable points there:

  • Client-side personalization is very limiting. Duh.
  • Allow pseudonymous access if you can. OK.
  • In collaborative filtering systems, perturb input data to hide users’ true values or deliberately introduce noise in the data, so that users can plausibly deny responsability for any potentially embarrassing data. Interesting ideas.

Intriguingly, he mentions a peer-to-peer approach to collaborative filtering that “allows users to privately maintain their own individual ratings, and a community of users to compute an aggregate of their private data…using homomorphic encryption…[and then for] personalized recommendations to be generated at the client side”. However, no citation for this work is provided.